Hydrocarbons, such as crude oil produced from underground reservoirs, often contain many compounds which are entrained within the crude oil. For example, an oil well will frequently produce large quantities of water, gas, carbon dioxide, solids and crude oil. To facilitate the pumping of the oil from an underground reservoir, devices such as gas anchors are commonly used to prevent large quantities of gas from being produced with the oil. If gas is produced with the oil, gas locks can prevent the efficient operation of the pumping mechanism. In addition, gas anchors and other devices can be used to prevent solids in the production fluids from being drawn into the pumping mechanism.
In the production of fluids from an underground reservoir, paraffin compounds associated with the hydrocarbons may solidify and coat the surfaces of downhole equipment. The solidification of paraffins may be due to a lower temperature which causes the crystallization of the paraffin, or may be due to the reaction of paraffin compounds with water and other fluids produced from the reservoir. In any event, the accumulation of paraffin solids on production equipment can impair the operation of the equipment.
Different techniques have been developed to remove the accumulation of paraffin solids from downhole equipment. For example, U.S. Pat. No. 4,011,906 to Alexander, et al. discloses a device which uses hot water to remove paraffin deposits from production tubing. In U.S. Pat. No. 4,138,931 to Hermann, et al., a hydraulic pump inhibits the formation of deposits by using plungers to create a fluid flow which produces a scrubbing effect on the cavity surface. In U.S. Pat. No. 194,704, to Means, water is removed from the well bore to prevent paraffin from forming in the well.
These techniques do not prevent the accumulation of paraffin deposits but are designed to remove the paraffin after it has accumulated. Accordingly, a need exists for a process and apparatus which can prevent the accumulation of paraffin deposits in downhole equipment.